1. Field of the Invention
The present invention relates to a oneway clutch as well as an outer race-retainer assembly for a oneway clutch, suitably used for an automatic transmission, etc., of a car.
2. Related Background Art
A oneway clutch for an automatic transmission of a car has seen increasingly wide-spread use in automatic transmission vehicles.
In the conventional oneway clutch device of this kind, each of torque transmitting members disposed radially between an inner member and an outer race member which is concentric with the inner member can take a torque transmitting position at which the inner member and the outer race member are united integrally and a non torque transmitting position at which the inner member and the outer race member may be rotatable relatively to each other. Such torque transmitting members have been held by a retainer made of metal with biasing members. The retainer is fixed to the outer race member by two caulked side plates in the axial direction and through block bearings in a circumferential direction.
Thus, an outer race-retainer assembly is formed, and assembling of an inner member with the outer race-retainer assembly completes a oneway clutch.
More in detail, the metal retainer in the conventional structure is formed by first and second annular side members extended radially at both sides in the axial direction and pole portions connecting the first and second annular side members. In apertures defined by the first and second annular side members and the pole portions, the torque transmitting members and the biasing members for biasing the corresponding torque transmitting members to the torque transmitting positions are fitted or held, and also block bearings for positioning the retainer in the circumferential direction with respect to the outer race member are fitted or held, respectively. The positioning of the retainer in the circumferential direction with respect to the outer race member is effected by the first and second annular side members which sandwich the outer race member therebetween.
Since the metal retainer in the conventional oneway clutch has such a structure as described above, one of the first and second annular side members and the pole portions connecting therebetween can be made by punching an integral metal plate and properly bending it, but the remaining or other annular side member has to be prepared separately. After the former (that is, the unitary structure of the one of the first and second annular side members and the pole portions) is fitted into the outer race member, the block bearings are inserted from the axial direction into the unitary structure and the latter (that is, the other annular side member) is caulked to thereby pinch and fix the block bearings, thereby completing the retainer.
The metal retainer in the conventional oneway clutch device has a complicated structure as described above, and the method of manufacturing such retainer is also complicated, which results in a large number of manufacturing steps and a high manufacturing cost.